import java.util.Scanner;

public class Zuhe1 {
      public static void main(String [] args) {
          Scanner reader=new Scanner(System.in);
          int n = 5;
          int m = 2;
          int a;
          int b;
          int c;
          a=fact(n);
          b=fact(m)*fact(n-m);
          c=a/b;
           System.out.println(c);
       }

       public static int fact(int n) {
          if (n == 0)
              return 1;
          else
              return n * fact(n-1);
     }
}
